This example demonstrates an interactive smiley face rendered as an SVG circle that follows the user’s mouse movement across the screen. Built with React (using hooks such as `useState` and `useCallback`), the application captures `clientX` and `clientY` coordinates from the SVG’s `onMouseMove` event and updates the circle’s center position accordingly. The visualization uses a production build of React 16.9.0, with the DOM managed via `ReactDOM.render` into a root div. The face itself is simplified to a single yellow circle with a black outline, with no static facial features visible.